Cooling-retarder for drawing glass



UNITED STATES Patented January 12, 1904.

i PATENT OFFICE.

LINCOLN THORNBURG, OF GAS CITY, INDIANA, ASSIGNOR TO THE WINDOW GLASS MACHINE COMPANY, A CORPORATION OF NEW JERSEY.

COOLING-RETARDER FOR DRAWING GLASS.

SPECIFICATION forming'part of Letters Patent N 0. 749,680, dated January 12, 1904.

Application filed April 25, 1903. Serial No. 154,273. (No model.)

To @Zlio/2,0771, it may concern.'

Be it known that I, LINCOLN THORNBURG, of Gas City, Grant county, Indiana, have invented a new and useful Cooling-Retarder for Drawing Glass, of which the following is a full, clear, and exact description, Areference being had to the accompanying drawings, forming part of this specification, in which- Figure 1 is a partial side elevation showing cylinder-drawing apparatus provided with my improved shield or cooling-retarder. Fig. 2 is a similar view looking at the opposite side, and Fig. 3 is a bottom plan view of the shield.

My invention relates to the drawing of glass articles from a bath of molten glass, and is designed to enable long articles-such as cylinders, sheets, &c.-to be drawn. Heretofore in the drawing of such articles after the bait has been drawn up a certain distance from the bath the contraction ofthe metal of the bait at the juncture with the glass due to cooling will crack the glass and the article will drop. My invention overcomes this difficulty and enables the operator to draw cylinders, sheets, or other articles of almost any desired length; and it consists in providing means for retaining the heat at the juncture of the bait and the glass, so that cracking will not occur, and consequently the article will be properly supported throughout the drawing operation. The retaining means consists, practically, of a shield which surrounds the bait and prevents rapid radiation of heat therefrom, though I may use means for applying heat to thebait or the glass at the juncture, the object being to keep the bait at the desirable temperature at such point. Y

In the drawings, in which I show one form of shield arranged for use with a blowpipe for drawing cylinders, 2 represents the blowpipe, having a ring or collar 3, by which it is supported on the vertically-movable drawingframe. This blowpipe is provided with the usual head l at its lower end, this head being usually conical and hollow, so that the air supplied to the pipe will pass down through it into the cylinder being drawn. After the bait, consisting of this pipe, which has been previously heated, is lowered into the bath it is then raised and the neck portion 5 of the hollow cylinder is formed. Air is then admitted to swell the glassv out to the desired size of the cylinder 6, and after the bait has been raised a short distance above the bath during the drawing operation the annular shield 7 is clamped around the pipe and hangs upon its head. This shield is preferably of conical form, made in two pieces, which are hinged together at one side by the hinges 8. I also show a spring-hinge device 9, by which the two sections of the shield are normally held in closed position, and to open the shield I provide the oppositely-located handles l0 l0. The shield is preferably lined with non-conducting material, such as asbestos board 1l, this layer being secured within the two sections by rivets 12 or in any other desirable manner. j

In using the shield the operator opens it against the spring-pressure and applies it to the pipe, the spring-pressure holding it closed, so that it hangs upon the ball or head of the blow-pipe during the remainder of the drawing operation. It has been found in practice that this shield -will act eiiiciently in retaining the heat, so that when the cylinder is lowered and severed from the pipe the ball or head of the pipe will be still at a low red heat.

The advantages of my invention result from the capability of drawing articles of any desired length, since the cracking away of the article from the bait is prevented.

A` gas-burner may be provided to supply heat to the lower portion of the bait, and many other variations may be made in the form and arrangement of the device without departing from my invention. By the words coolingretarder in my claims I intend to cover not only a device which holds the heat of the bait, but also a device for supplying additional heat which is found desirable.

I claiml. In glass-drawing apparatus, the combination with the bait, of a cooling-retarder arranged to prevent cooling of said bait; substantially as described.

2. In glass-drawing apparatus, the combination with a metal bait, of a shield arranged glass articles, of a cooling-retarder arranged to retard cooling of the bait at its juncture with the glass; substantially as described.

5. In glass-drawing apparatus, a metal bait and a surrounding shield for the same made of a plurality of hinged parts clamped around the bait; substantially as described.

6. In glass-drawing apparatus, a hollow pipe having a lower head, and a removable shield surrounding and supported upon said head; substantially as described.

7 In glass-drawing apparatus, the combination with a metal bait, of an annular shield having a non-conducting lining', and removably clamped around the bait; substantially as described.

In testimony whereof I have hereunto set my hand.

his LINCOLN Y k THORNBURG.

mal'

Witnesses:

L. M. REDMAN, H. M. CoRWIN. 

